Resource allocation performance analysis and idle resource reallocation for FOV-limited indoor VLC networks

Visible light communication (VLC) networks based on multiple access points (APs) have gained significant attention in enhancing indoor communication coverage and transmission capacity. Since interference can significantly impact the quality of VLC links, this paper investigates and compares the performance of three resource allocation (RA) schemes based on the user equipment (UE) location to avoid interference under specific VLC deployments. Towards this end, we first derive statistical channel gain models in different overlap settings of coverage areas of optical APs according to the structural information, assuming that the UE distribution follows the Poisson point process (PPP) model. Then we derive the expressions for the performance metrics of the three RA schemes. Meanwhile, we construct a conflict graph to reveal potential interference relations and propose an idle resource reallocation policy (IRRP) in the case of low UE density. Finally, simulation results are provided to verify the correctness of derived expressions. It is shown that the performance of field-of-view (FOV)-limited VLC networks depends heavily on the RA schemes free of intercell interference (ICI). Without resource reallocation, more detailed resource division leads to worse system performance. With a user density of only
$0.1\;{{\rm UE/m}^2}$
, the IRRP can even enhance the area spectral efficiency (ASE) of the proposed joint transmission (JT) scheme by 330% under linear deployment and 780% under hexagonal deployment, making the JT scheme the best among all relevant schemes in most situations.